I am getting SelectorNotFoundException while reading an OCR text using Google OCR. It will not occur frequently. Can somebody help on this.

SelectorNotFoundException does not have anything to do with OCR by itself.
Only thing that comes to mind is check that the selector you’re providing for the element (window?) that you want to scrape works in all cases - start with those that currently fail and check the patterns.

I have re-scrapped. It works for initial 1-2 times. Again the error comes out then.